I am deeply sorry that I (as a user) tried already a second time to get engineering to solve a problem caused by them! (...) Quite frankly: As a user/customer I do not care what information's are exchanged and where and how and and and.... -- I am interested in: Does it work or not!
Okay, let me try again to correct the misconception here.
FG is not industry, it is OpenSource. You are not a customer, you obtained 'the product' under the GPL license for free with no warranty or claim that it works for you. I am not engineering, I am a volunteer who codes as a hobby and donates coding time to a software you happen to enjoy now and then. I am not a support desk either, I am a volunteer who helps people around in the forum on his spare time.
So - it does not work - we know that. As part of the FG project, my interest is in determining - is there need for any action from the FG project?
The answer is no - you are talking to the wrong people. If you were in the MS Window$ support forum, they would tell you that they didn't write OR or FG and can't fix either. I tell you that FG-side all is a done deal [1] and that the only person who can fix things is the OR maintainer - so you need to make a bug report to him. Nothing else will make OR compatible again.
* I know people that never updated there "wonderful working" FGFS over years! It maybe a good point to "urge" them to update - but till now I saw it as a big plus for FGFS that that was not needed!
If you keep your own setup (MP server, aircraft repository,...) then this is true - but the FG-side infrastructure (terrasync server, some MP servers, aircraft repository...) is geared towards the latest FG version, and if you want terrasync access, you need to respect the current terrasync protocol, if you want to run a new aircraft, you need to have a binary which supports its effects, shaders, FDM tags, animations etc.
It is unreasonable to expect from people who donate time and money to supply this infrastructure for the project that they triple their effort and expenses to keep everything backward-compatible. If you want that kind of infrastructure, you need to come up with a plan to finance it.
[1] The plans for changes to the MP protocol FG-side have been properly announced in advance on the mailing list, have been discussed, it was generally felt (especially by people doing MP a lot!) that the advantages are worth the breakage that is caused and now the changes are done with a very low probability to be reverted. Anyone who feels that his voice should have been heard is encouraged to participate in the discussions on the mailing list and say his piece in time, not when the train has passed.